Method of forming large tank structures of filament windings



A. L. BASTONE METHOD OF FORMING LARGE TANK STRUCTURES OF FILAMENT WINDINGS Filed May 18, 1966 4 Sheets-Sheet 1 AUX/0R5! L. 5/157'0/1/5 INVENTOR ATTORNEYS Dec. 1969 A. L. BASTONE 3,483,954

METHOD OF FORMING LARGE TANK STRUCTURES OF FILAMENT WINDINGS Filed May 18, 1966 4 Sheets-Sheet 2 ATTORNEYS Bee. 9, 1199 A. 1.. BASTONE A W METHOD OF FORMING LARGE TANK STRUCTURES OF FILAMENT WINDINGS Filed May 18, 1966 4 Sheets-Sheet 5 A A/fl/afn/ L, 54am;

I N V EN TOR BANDS TO MANDREL ATTORNEYS Den. 9, 1969 A. BASTONE 3,483,854

METHOD OF FORMING LARGE TANK STRUCTURES OF FILAMENT WINDINGS Filed May 18' 1966 4 Sheets-Sheet 4 Q \g Q g w Z \k 33 Qw 3 a: j M: ms Q:

4/1/0215 1. bi /570w INVENTOR.

United States Patent M 3,483,054 METHOD OF FORMING LARGE TANK STRUC- TURES OF FILAMENT WINDINGS Andrew L. Bastone, Granville, Ohio, assignor to Owens- Corning Fiberglas Corporation, a corporation of Delaware Filed May 18, 1966, Ser. No. 551,092 Int. Cl. B65101 81/02 US. Cl. 156-161 3 Claims ABSTRACT OF THE DESCLOSURE Process for filament Winding large tank structure by applying continuous rovings in uniform spiral fashion under uniform and constant tension, using a static set of conditions between the creel and the traverser, wherein a stationary package with inside pull of the roving is employed in a particular orientation route from the package to the mandrel.

This invention relates to filament winding; and, more particularly, to an improved process for winding large tank structures whereby the continuous rovings are applied in uniform spiral fashion under uniform and constant tension.

THE PROBLEM In order to make tanks and analogous fluid-handling vessels of high strength, continuous glass filaments are wound over the surface of a winding mandrel in a spiral pattern. Glass filaments are of very high strength and when embedded in a matrix resin, provide a very strong structure of low thickness.

It is important in the filament winding process that the continuous rovings be laid onto the winding mandrel in properly oriented, spiral form, all along the length of the mandrel, and under constant and uniform tension. If this is not done, a nonuniform structure will be the result and strength defects are usually bound to appear.

As sometimes practiced, the creel holding the roving packages is placed oif to one side of the winding mandrel and the roving is fed to a guide and wet-out tank carried by a traversing carriage, movable along the length of the mandrel, and adjacent to the mandrel. Under this previous and undesirable sitaution, the roving packages were turned so that the take-ofi of the roving was from the outside. The inertia of the roving packages caused substantial trouble, even though very expensive tension devices were utilized.

It will thus be understood that when the traverser is in direct alignment with the creel, and the traverser is at the center of the mandrel during a traverse, the roving is at the desired tension. However, this ideal tension and orientation situation exists only once in each direction of traverse along the length of the mandrel.

When the traverser reaches the end of the mandrel, with the roving under tensionand suddenly reverses, the roving goes slack for an instant due to the overrun caused by the inertia of the rotating roving packages. Thus, winding tension drops at a critical point in the processthat is, at each end of mandrel. The system must then catch up with itself and overcome the slack which developed on reversal of the traverser.

From the foregoing, it will be understood that there are places in the Wound tank adjacent to the ends, where the tension in the roving is drastically different from the tension at the centerthe only place where uniform and ideal conditions exist.

It will also be evident from the foregoing, that roving orientation relative to the mandrel will change from end 3,483fi54. Patented Dec. 9, 1969 to end. It only remains constant at the centerduring those instances when the traverser is in alignment with the creel.

Another reason why the rovings are paid off the packages peripherally, using a rotating package, is to avoid twisting of the rov ng as it is laid on the mandrel. If the packages are held still and the roving. paid off the outside, over end, the twisting of the roving will be so severe as to render unsatisfactory a tank wound therefrom. Twisting, binding and end loss of roving are reasons why the system has utilized a rotating package.

The foregoing discussion of the problem indicates that the ideal situation is to have the rotating roving package move in synchronized relationship with the traverser so that the rovings are kept under constant tension and under constanly the same alignment relative to the wind ing mandrel, as distinguished from the constanly fluctuatin g problem system described above.

It is accordingly an important object to provide a novel filament winding process and system.

A further object is to provide a novel filament winding process and system utilizing a static set of conditions between the creel and the traverser, thereby providing constant tension on the roving, and the same orientation of roving feed out from package to traverser, from end to end of the mandrel.

A' further object is to provide a filament winding system wherein constant conditions are preserved between the creel and the traverser, using a rotating package with outside pull or roving from the package.

A further object is to provide a filament winding system wherein constant conditions are preserved between the creel and the traverser, using a stationary package with inside pull of roving from the package.

These and other objects of this invention will become apparent from the following description and appended claims, and by reference to the accompanying drawings forming a part of this specification, wherein like reference characters designate corresponding parts in the several views.

FIGURE 1 is a fragmentary, end elevational view illustrating filament winding apparatus, as background for the present invention;

FIGURE 2 is a fragmentary, end elevational view of an overhead traveling creel system of the present invention, for alternately winding side-by-side mandrels;

FIGURE 3 is a fragmentary side elevational view, taken along the line 33 of FIGURE 2;

FIGURE 4 is a schematic, end elevational view of the process provided by the system of FIGURES 2 and 3;

FIGURE 5 is a top plan view, illustrating the manner in which the principle of the system of FIGURES 2, 3 and 4 is applied to a stationary roving package, using inside pull, with axial feed of roving relative to the mandrel;

FIGURE 5a is a perspective view of the resin tank, for clarification; and

FIGURE 6 is a top plan view, illustrating a second embodiment of the stationary package system, with transverse roving feed relative to the orientation of the axis of the mandrel.

THE INVENTION: BROAD ASPECTS Briefly, the present invention encompasses a process and apparatus system for producing filament wound tank structures wherein a constant orientation and tension is provided between the creel and traverser. Further, the present invention provides for the use of either rotating roving packages, with outside take-off; or stationary roving packages, with inside pull from the package.

Further, a novel overhead creel system is provided by the invention, on which either rotating or stationary packages can be placed-for serving a traverser associated with a winding mandrel, thereby making it possible to serve side-by-side winding mandrels. This is eifective to increase production by the fact that while a wound structure is being cured and removed from one mandrel, another filament wound structure can be in the process of manufacture on the adjacent mandrel, thereby providing continuous use of the roving serving creel structure.

BACKGROUND FOR THE INVENTION; FILAMENT WINDING ONTO A MANDREL, FIGURE 1 As shown in FIGURE 1 a winding mandrel is designated 20. This is a hollow, open-end, frusto-conical shell. The mandrel 20 is supported on a rotatable shaft 22. Shaft 22 is rotatably mounted at one end in a cantilevered manner, with the other end free. The large end of the mandrel 20 is placed at the supported end of the shaft 22 and the small end is free. The frusto-conical taper of the mandrel 20 and the free small end provide part release on completion of curing of the wound tank part.

Support spiders 24 radiate outwardly from the shaft 22 and are fastened at their outer ends to the interior of the mandrel 20.

Rotation of the mandrel 20 is provided by a low speed geared motor mechanism not shown.

The apparatus and manner of forming the side wall lay-up to produce a tank wall are not shown because they are not pertinent to the present invention. It can be pointed out, however, that such apparatus is effective to apply a layer of material 26 over the outer surface of the roving 20. The layer 26 is essentially a substantial body of chopped strand and resin, to wit, a resin-rich bodying layer for stiffness.

At the top there is provided a radiant unit 28 for application of heat, in order to cure the resin-containing side wall.

Along one side of the mandrel 20, there is provided a trackway system 30 that includes a frame structure 32 upon which two spaced tracks 34 are mounted in horizontal, aligned relationship. A carriage 36, provided with wheels 38, travels back and forth along the tracks 34.

A chain 40 is mounted for movement along one side of the track system 30 and is lapped over sprockets 42, rotatably mounted at each end of the frame 32. A shear pin-type connection 44 is provided between the carriage 36 and the chain 40. This is effective to disengage the ap paratus in the event of malfunction.

Traverse of the carriage 36 is effected by a gear motor 46, that is suitably programed from a control box 48. The gear motor 46 is connected into the chain 40 system by means of a sprocket 50 carried on the output shaft 52.

This equipment is efiective to move the carriage 36 back and forth along the full length of the mandrel 20. As it does, continuous rovings 54 are saturated with liquid resin and applied in a criss-cross laid layer over the previously applied layer 26.

The Wetting of the continuous rovings 54 is effected by using a container 56. The container 56 is mounted on top of the carriage 36 and the continuous rovings 54 are fed through a body of liquid resin 58, retained at an appropriate level within the container 56. By suitable mechanism, to be described, the continuous rovings 54 are permitted to pick up appropriate amounts of liquid resin to form the filament wound overlay.

The rovings 54 are fed from packages, not shown in FIGURE 1, that are mounted some distance from the traversing mechanism 60 in accordance with the principles of this invention. According to the invention, a constant set of conditions is provided between the creel, holding a plurality of roving packages, and the traversing mechanism 60. It will be evident from FIGURE 1 that constant conditions are provided for the rovings 54, passing from the traverser 60 onto the mandrel 20.

A guide roll 62 is rotatably mounted on a bracket 64, extending outwardly from the carriage 36. Additionally, a gathering ring 66 is positioned ahead of the guide roll 62 to group the several rovings 54 into aligned relationship as they pass over the roll 62. The gathering ring 66 is also supported by the bracket 64 that is extended to the left, in FIGURE 1, for such purpose.

The combination of the gathering ring 66 and the guide roll 62 is eifective to orient the rovings 54 for proper angle of entry into the bath of liquid resin 58 contained within the tank 56.

A dip roller 68 is mounted Within the tank tnd the rovings 54 pass beneath this element and are thereby submerged in the body of liquid resin 58. Aligned squeegee bars 70 are also supported within the tank 56. As the wetted rovings 54 pass between the bars 70, the amount of resin is reduced to a selective amount. The bars 70 can be adjusted relative to one another for appropriate resin pick up.

THE TRAVERSE OF THE CONTINUOUS ROVINGS 54 As the mandrel 20 is turned, carriage 36 is moved back and forth along the tracks 34. By so operating, the Wet rovings 54 are laid onto the previously applied resin-rich shell layer 26. Because of the traverse of the wetted rovings 34 along the surface of the mandrel 20, the rovings are laid on in a spiral manner in one direction and then on reversal, are criss-crossed by application of each subsequent layer.

THE IMPROVEMENT OF THE PRESENT INVEN- TION: FIGURES 2, 3 AND 4, THE OVERHEAD CREEL USING ROTATING ROVING PACKAGES In one embodiment of the present invention, a rotating roving package 72, with outside take-off, is utilized. It is desirable to use this type of roving in a production operation operation because of the favorable economic factor. However, as described above, the inertia of the rotating package 72 has produced problems of overrun at the ends of the mandrel. However, by this embodiment of the invention, such problems are solved.

As shown in FIGURES 2, 3 and 4, a pair of opposed mandrels 74 and 76 are provided; or can be provided in a very eflicient production operation. These are adapted to be rotated, as described relative to FIGURE 1. A traversing mechanism 78 is schematically illustrated.

Since an important advantage of this embodiment of the invention is the use of two side-by-side mandrels 74 and 76, the entire traversing mechanism 78 is so designated, difierently from FIGURE 1, because it is adapted to be operated in two positions, namely adjacent to either of the mandrels. For this purpose, a subcarriage 80 is provided which can be moved transversely between the mandrels 74 and 76. The Wet-out mechanism, designated 82, is of the turntable-type. This unit is adapted to operate in either the solid line position, adjacent to mandrel 74, or in the dotted line position, adjacent to mandrel 76, as shown in FIGURE 2.

The rollers 84, at the bottom, are provided for movement of the subcarriage 80, and thus the entire traversing mechanism 78 to a proper position relative to either of the mandrels 74 or 76. Thus, the subcarriage is adapted for carefully aligned lateral movement between mandrels 74 and 76. A suitable track system, not shown, is provided for such proper alignment.

It is to be understood, of course, that the wet-out mechanism 82 is movable axially along the length of each of the mandrels 74 and 76 for the filament winding operation, as described relative to FIGURE 1.

From the foregoing it will be understood that the fixed set of conditions between wet-out unit 82 and either of the mandres 74 and 76 is provided, as described relative to FIGURE 1.

THE INVENTION-FIXED CONDITIONS BETWEEN CREEL AND WET-OUT TRAVERSER The important contribution provided by the present invention is a traveling overhead creel 86. Vertical frame members 88 support a pair of spaced tracks 90. The tracks 90 are positioned adjacent to the ends, and outboard of .the mandrels 74 and 76 for clearance.

A carriage 92 for the overhead creel 86 is provided with two spaced pairs of wheels 94, which are movable on tracks 90. Carriage 92 comprises a pair of spaced lateral beams 96, which connect the ends of a pair of spaced longitudinal beams 98, shown in FIGURE 3. The longitudinal beams 98 span the distance between the spaced lateral tracks 90.

The overhead creel 86 is essentially a movable frame or carriage upon which a plurality of roving packages 72 are rotatably supported. The ends comprise transverse plates 100, between which longitudinal support members 102 extend. Wheel support plates 104 are provided at the ends, and wheels 106 are thereby supported at each corner of the movable creel 86.

Support plates 108 for the roving packages 72 are.

provided in spaced array along the length of the movable creel86. ,In the exemplary embodiment shown, four rows of support plates 108 are provided for four rows of eight roving packages each. From each plate 108, there is extended a rotatable shaft 110 upon which a roving pack age 72 is held in place as by means of a suitable retainer nut 112.

The rovings 54 are each directed downwardly to collecting guide eyes 116, through each of which a plurality or rovings are passed. This converges and concentrates the rovings into a fiat band arrangement as illustrated in FIGURE 3. The rovings are passed through the resin dip tank 56 as such a fiat band, in the manner illustrated in FIGURE 1, and are thereafter transversed onto the surface of a mandrel 74 or 76. From the dip tank 56 onto the surface of the mandrel 74 or 76, the orientation of the rovings 54 is as illustrated in FIGURE 1.

From the foregoing it will be understood that conditions between the roving packages 72 and the dip tanks, schematically illustrated as 56, are always maintained constant. This is brought about by the fact that both the overhead creel 86 and the resin dip tank apparatus 56 are traversed simultaneously togeher along the length of a selected mandrel 74 or 76. When a reversal of the apparatus takes place at the end of a mandrel, the roving pay out retains a smooth and uniform rate. There is no slack development as set forth in the prior problem situation discussed above. Reversal at the ends of the mandrel is easy and smooth.

From FIGURE 2 it is clearly apparent that constant conditions of orientation are provided between the rotating roving packages 72 and the resin wet-out traversing mechanism 56.

THE IMPROVEMENT OF THE PRESENT INVEN- TIONFIGURE 5; THE END STATIONARY CREEL USING FIXED ROVING PACKAGES FIGURE 5 illustrates application of the present invention, in one embodiment, to a stationary creel positioned in axial alignment with the mandrel. This embodiment is applicable to use with two side-by-side mandrels 74 and 76 as in FIGURES 2, 3 and 4. The traverser mechanism 118 is reversible in order that it can alternately serve each of the mandrels 74 and 76. The solid outline position is representative of the service to the mandrel 74 and the dotted outline position to the mandrel 76. In this embodiment of the invention, guide eyes 120 and matching guide bars 122 are provided near the resin tank 56 to collect several rovings 134 into a single group to be fed to immersion rings 124 positioned within the body of liquid resin 58 retained in the resin tank. The resin tank 56 has front openings 57, with wiper bars 59 6 to hold back excess resin, see FIGURE 5a. Catch plates 61 also can be used as in FIGURE 6.

The roving creel 126 comprises any suitable fixed support for the roving packages 128. These are so designated because they are different from the 35 pound packages of 60 end equivalent rovings used in FIGURES 1-4. The roving used is a type 30 inside pull package. This is a 20 end equivalent material and will provide inside pull without excessive twisting.

Simple tension bars 130 are mounted in cooperating pairs above each roving package 128. Guide eyes 132 are mounted on a suitable support in aligned relationship above the roving packages 128, in properly orientated relationship thereto. As an example, one hundred and fifty-three roving packages 128 can be used passing three rovings 134 through each of fifty-one eyes 132.

From the fixed guide eyes 132, the continuous rovings 134 move in a straight line relationship to the guide eyes and mating guide bars 122. As in the embodiment of FIGURES 2, 3 and 4, a constant set of conditions is thereby provided between the creel 126 and the traversing mechanism 118. Only the free length of the continuous rovings 134, between th guide eyes 132 and 120, will ever change. However, this does not change the equilibrium of the system because the roving packages 128 do not rotate. Therefore, there is no inertia factor to cope with in this system and reversal at the ends of the mandrel is easy and smooth.

The dotted outline position of traverser mechanism 118 in FIGURE 5 illustrates that a roving creel 126 can be used at each end of the mandrels 74 and 76, if desired. This will require rethreading of the rovings from one creel to the other when a mandrel change is made. However, in this regard, it will be evident that only a single creel will be used, as illustrated, when appropriate turnaround mechanism is provided adjacent to the eyes 120. Thus, when the traverser mechanism 118 isrotated as at the dotted outline position, the rovings would continue to be fed from the single creel 126, illustrated. Thus, substantial versatility of roving feed is provided in accordance with the present invention.

THE IMPROVEMENT OF THE PRESENT INVEN- TION-FIGURE 6; THE TRANSVERSE STATION- ARY CREEL USING FIXED ROVING PACKAGES In the embodiment of FIGURE 6, the stationary creel 126, the same type as in FIGURE 5, is positioned to feed rovings 134 transversely to the axis of the mandrel 136. This is actually analogous to the problem system discussed above. However, the problem of slack development in the rovings is eliminated here by the use of inside pull roving packages 128, as in FIGURE 5. This embodiment is practically applicable to use with only one mandrel 136 because the distance 138 between the stationary creel 126 and the traverser roving wet-out mechanism 118 is substantial. For example, in this type of system, using an exemplary ten foot long winding mandrel, it is customary to place the creel 126 from 25 feet to 30 feet off to one side of the mandrel so that the rovings have a relatively free sweep of the length of the mandrel.

In this embodiment, guide eyes 120 and matching guide bars 122, are provided near the resin tank 56 to collect the rovings 134 into band-like groups to be fed to immersion rings 124 positioned within the body of liquid resin 58 retained in the resin tank 56.

The roving creel 126 is as defined in FIGURE 5, and comprises any suitable support for stationary roving packages 128. These are of the type 30 inside pull construction as discussed relative to FIGURE 5.

Simple tension bars are mounted in cooperating pairs above each roving package 128. A plurality of eyes 132 are mounted on a suitable support in aligned relationship above the roving packages 128 in properly oriented configuration.

From the fixed guides 132, the rovings 134 move in a converging fan pattern to the more closely spaced guide eyes 120 and matching guide bar sets 122. This is analogous to the embodiments of FIGURES 2-5 because a constant set of tension conditions is established between the creel 126 and the traversing dip tank 56. Due to the fact that the roving packages 128 are stationary, and the rovings 134 themselves have negligible inertia, there is no slack development at the ends of the mandrel 136 when the traverser 118 reverses, as in the problem system described above.

SUMMARY By the present invention, there has been provided a novel system for filament winding wherein constant conditions are established between a roving creel and a traverser running alongside the winding mandrel in a to and fro manner. By the present invention, either rotating, outside take-01f roving packages; or stationary, inside pull roving packages can be utilized. Substantial versatility is inherent in the present invention as will be clearly evident to those skilled in the art.

I claim:

1. In a process for filament winding an endless Wall structure on a rotating mandrel having a horizontal axis, and using roving packages to supply the filament Winding medium, and a wet-out apparatus for the roving that traverses parallel to the axis of the mandrel, along the mandrel, and from which wet-out apparatus the roving is supplied onto the mandrel, the steps of fixing the roving package at a point in space,

traversing the roving wet-out apparatus along the mandrel, parallel to the axis,

simultaneous with said traverse, feeding roving from the roving package to the wet-out apparatus under constant tension conditions between the roving package and the wet-out apparatus by pulling the roving from the inside of the stationary package to a point above the axis of the mandrel, then moving the roving downwardly into the wet-out apparatus; and thereafter moving the roving from the wet-out apparatus upwardly and transversely of the axis of the mandrel, onto the periphery of the mandrel.

2. The process according to claim 1, including moving the roving from the inside of the package under slight tension in a direction generally parallel to the axis of the mandrel into and through the wet-out apparatus.

3. The process according to claim 1, including moving the roving from the inside of the package under slight tension in a direction generally transverse to the axis of the mandrel and into the wet-out apparatus.

References Cited UNITED STATES PATENTS 3,025,205 3/1962 Young 156l69 3,249,312 5/1966 Current 24242 3,307,998 3/1967 Boggs 156425 XR 3,112,897 12/1963 Eshbaugh et al. 156169 XR PHILIP DIER, Primary Examiner US. Cl. X.R. 

